Yes, this is an actual newspaper article from 1860 - unbelievable!
"A fortnight since, there was a very remarkable scene in a creek close by the sea at Duxbury, Mass., between Plymouth and Marshfield. A small sail boat in coming up the creek from the ocean came upon a drove of porpoises. Other boats joined the first and drove the sea-monsters up the creek into water so shallow, that they could not easily make their escape. Some of the party in the boats began to shoot at the porpoises. Others with guns from the shore immediately joined them, and soon there was a general slaughter with guns and knives. The battle raged some time, when the entire drove, 75 porpoises, old and young were killed. The largest porpoise weighed 800 pounds."
Date: September 07, 1860
Paper: New London Daily Chronicle